Ram-up chill and chaplet studs



Oct. 8, 1968 w. P. WITTKE 3,404,726

RAM-UP CHILL AND CHAPLET STUDS Filed Deo. 30. 1965 Qfromsyf" UnitedStates Patent O 3,404,726 RAM-UP CHILL AND CHAPLET STUDS Walter P.Wittke, Rockford, Ill., assignor to Nasco, Inc., Rockford, Ill., acorporation of Illinois Filed Dec. 30, 1965, Ser. No. 517,673 7 Claims.(Cl. 164-357) This invention relates to studs used in molds havingcavities for receiving molten material to be cast and, moreparticularly, to the stud heads which are disposed within the packedmaterial forming the mold to hold the stems of the studs in the desiredpositions in the mold. The invention is particularly concerned with theheads of so-called chills which are disposed in larger zones of the moldcavity to carry away the heat of molten metal and accelerate the coolingin the larger zones, but also is applicable to chaplets for holding aloose core in place in the cavity as the molten material ows into thecavity around the core.

The general object of the present invention s to provide a new andimproved head construction which, as compared to prior constructions, ismore quickly and easily positioned in the mold material and providesbetter anchoring of the stud in the mold.

Another object is to provide an improved ram-up stud, that is, a studhaving a head around which the mold material is packed during forming ofthe mold, which insures that the mold material is packed in holdingengagement with all the exposed surfaces of the head.

A further object is to facilitate the removal of the head from the stemwhen the latter is embedded in the completed casting.

Still another object is to produce the improved ramup stud at a costless than the cost of prior ram-up studs.

Other objects and advantages of the invention will become apparent fromthe following detailed description taken in connection with theaccompanying drawings, in which:

FIGURE 1 isa fragmentary cross-sectional view showing a cast part in amold cavity provided with illustrative chill and chaplet studs embodyingt-he novel features of the present invention.

FIG. 2 is a fragmentary cross-sectional view of a pattern having theshape of the cast part in FIG. 1 and used to form the mold with thelstuds therein.

FIG. 3 is .an enlarged perspective view of a chill.

FIG. 4 is an enlarged fragmentary perspective view of a chaplet.

FIG. 5 is an enlarged fragmentary cross-section through the mold and thepattern showing the chill in side elevation.

FIG. `6 is a view similar to FIG. 5 showing the mold and the chill insection after removal of the pattern.

As shown in the drawings for purposes of illustration, the invention isembodied in a chill 10 and two chaplets 11 and 12 as used in aconventional mold which includes a cope 13 and a drag 14 having walls 15and 17 dening a cavity. Molten metal is introduced into the cavitythrough a gate 18 and suitable risers (not shown) which are employed asneeded. The metal shrinks as it 'solidies to form the cast part 19, andadditional Imetal flows into the cavity through the gate to make up forthis shrinkage. In some instances, however, narrow sections of the metalsuch as the section 20 in the gate passage tend to solidify before alarger central section and thereby prevent further ow of metal to thelarger section. This can result in defects in the casting.

To prevent such defects from forming, the chilll10 is inserted in thelarger section to absorb heat from the molten metal and cause this metalto cool and shrink before the smalle-1' section at 20 solidies. Suchchills have a stem 21 which is disposed in the mold cavity, and

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3,404,726 Patented Oct. 8, 1968 ice a head which is embedded in one wallof the mold to support the chill in the desired location in the cavity.The chaplets 11 and 12 are generally similar to the chill inconstruction and mounting but are used as positioning elements supportedon the walls of the mold and engaging a core 22 positioned in the cavityto form a recess at 23 in the casting 19. The chaplets hold the core inplace as the molten metal liows into the cavity around the core. Herein,the chaplet 11 is shown with its head embedded in the side wall 17 ofthe cavity and its stem 24 engaging the adjacent side of the core tohold the latter against lateral shifting. The head of the other chaplet12 is embedded in the top wall 15 of the cavity and with the stem 25thereof engaging the top of the core.

The primary structural difference between the chills and chaplets shownis in the stems. To effect rapid heat transfer and fusing of the heattransfer surface with the molten metal, the stem 21 of the chill 10 isknurled or serrated for increased surface area as compared to acylindrical stem. Since the important function of the chaplets is theholding of the core, the stems 24 and 25 may be simply cylindrical pins.It will be seen in FIG. 1 that the stems of both types of studs remainin the casting 19 and become integral parts thereof after the mold isremoved. The heads of the studs project out of the casting and arebroken off at the surface of the latter.

The present invention contemplates a new and improved construction ofheads for studs of the foregoing character, the improved heads morequickly and easily embedded in the mold material in precisely theposition desired and providing better anchoring of the studs after theheads are embedded in the Walls of the mold. To these ends, each headcomprises at least one section 27 of wedge-shaped or generallytriangular longitudinal crosssection tapering toward the adjacent end ofthe stem of the stud and joined at its smaller end 2S to the stem. Withthis arrangement, the material used to form the mold parts may be rammedaround the head in tightly packed holding engagement with the exposedsurfaces of the head to anchor the stud securely in place as an incidentto the forming ofthe mold.

In this instance, the head of the chill 10 comprises two conicalsections 27 coaxial with each other and with the stem and having amaximum diameter at the larger end of each section preferably the sameas the outside diameter of the stem 21. The smaller end 28 of the firstsection is integrally joined to the upper end of the stem, and thesmaller end 29 of the second section is joined to the larger end 30 ofthe rst section. While the degree of taper is not critical, I prefer ataper on the order of thirty degrees with the axis of the stud.

To form the mold with the chill 10 in place, the stem 21 of the chill isinserted in a closed bore 31 in a pattern 32 (FIG. 2) having the shapeof the cavity 19 to be formed. The bore is formed in the pattern in thelocation corresponding to the desired location of the chill, and itslength is selected to hold the outer end of the stem 21 substantially-ush with the outer surface of the pattern. When molding sand is packedaround the pattern and the protruding head sections 27 of the chill (seeFIG. 5), the granular sand can ow around the head sections and becomefirmly packed against the tapered side surfaces of the sections. Then,when the pattern is removed, the chill is suspended from the top wall 15of the mold as shown in FIG. 6.

Studs that are installed in this manner are called ramup studs in theart, in view of the ramming and packing of lthe sand around the heads.In prior ram-up studs, however, the heads have been flat plates or thelike fastened as by rivets to the stems, and the substantiallyperpendicular overhangs of such heads have prevented lirm packing ofsand under the heads.

Although the maximum diameter of the head sections 27 may be no greaterthan the outside diameter of the stem 21, a plurality of such sectionswith tapered side surfaces provide a holding surface area equal to orgreater than the area provided by flat heads. Moreover, the new stud canbe manufactured more economically than studs with riveted heads becauseof the one-piece construction that can be turned out in quantity usingbar stock and an automatic screw machine. Further, the narrowness at theline of joinder at 28 between the head and the stern is a convenientbreak-off point facilitating removal of the head from the completedcasting 19. This break-off point is formed automatically as an incidentto the shaping of the head.

As will be seen in FIG. 2, the illustrative chaplets 11 and 12 areinstalled in the same way, using bores 33 and 34 in the pattern 32 atthe desired location of the stems of the chaplets, and packing the sandaround the heads in firm holding engagement therewith. The packed sandcooperates with the tapered sides of the head sections 27 to initiallyhold the chaplets in place relative to the mold parts, and the flats 30forming the larger ends of the sections cooperate with the sand inholding the chaplets against movement deeper into the sand. These flatspreferably are perpendicular to the longitudinal axes of the chaplets. Acylindrical section 35 (FIGS. 1-3) may be formed at the end of eachchaplet stem to join the first conical section 27 to the stem 24, 25while providing a stop for abutting against the outside of the pattern32 as shown in FIG. 2. Of course, the flat outer surface 37 of thissection bears against the packed sand to assist in holding the headagainst movement into the sand.

In selecting the number of head sections 27 to be used on a particularstud, `consideration is given to the weight of the stud to be supportedon the mold and the surface area necessary to prevent movement of thestud. It is a very simple matter to add or remove head sections inmaking up the studs.

I claim as my invention:

1. In a mold having walls composed of packed granular material defininga cavity for receiving molten material to be cast, the combination withsaid mold of a stud having a stem projecting into said cavity from oneof said walls, and a head joined to one end of said stem and disposed inthe packed material forming said one wall, said head having at least onesection of triangular longitudinal cross-section tapering toward andjoined to said one end with said granular material packed around thehead in holding engagement with all exposed surfaces of said section.

2. The combination defined in claim 1 in which said head comprises aplurality of generally conical sections coaxial with each other and withsaid stem and each tapering toward the stem, said sections and said stembeing integrally joined together.

3. In combination with a mold having a cavity for receiving moltenmaterial to be cast, a stud having a stem for projecting into saidcavity from a wall of said mold, and a head on one end of said stemadapted to be packed in the material forming said wall, said head havingat least one section of wedge-shaped longitudinal cross-section taperingtoward and joined to said one end to facilitate packing of the moldmaterial around the head to hold the latter in the mold.

4. For use with a mold having a cavity for receiving molten material tobe cast, a stud having a stem for projecting into said cavity from awall of said mold, and a head on one end of said stem adapted to bepacked in the material forming said wall, said head having at least onesection of wedge-shaped longitudinal cross-section tapering toward andjoined to said one end to facilitate packing of the mold material aroundthe head to hold the latter in the mold, said stud further including asecond similar section tapering toward said stem and having asubstantially flat surface facing away from said stem, said secondsection being joined at its smaller end to the larger end of said onesection.

5. A stud as defined in claim 4 in which said sections are conicallyshaped and coaxial with each other and with said stem.

6. A stud as defined in claim 5 in which said stem is generallycylindrical and the maximum diameter of said sections is approximatelythe same as the diameter of the stem.

7. A stud as defined in claim 5 in which said head includes acylindrical section larger than said stem joined to said one end betweenthe latter and the first conical section.

References Cited UNITED STATES PATENTS 1,924,280 8/1933 Hobart 164-3991,945,358 1/1934 Raible 164-399 2,170,103 8/1939 Westover 164-357 XFOREIGN PATENTS 56,801 7/1912 Austria. 300,452 9/1932 Italy.

T. SPENCER OVERHOLSER, Prlmu'y Examiner.

E. MAR, Assistant Examiner.

1. IN A MOLD HAVING WALLS COMPOSED OF PACKED GRANULAR MATERIAL DEFININGA CAVITY FOR RECEIVING MOLTEN MATERIAL TO BE CAST, THE COMBINATION WITHSAID MOLD OF A STUD HAVING A STEM PROJECTING INTO SAIDCAVITY FROM ONE OFSAID WALLS, AND A HEAD JOINED TO ONE END OF SAID STEM AND DISPOSED INTHE PACKED MATERIAL FORMING SAID ONE WALL, SAID HEAD HAVING AT LEAST ONESECTION OF TRIANGULAR LONGITUDINAL CROSS-SECTION TAPERING TOWARD ANDJOINED TO SAID ONE END WITH SAID GRANULAR MATERIAL PACKED AROUND THEHEAD IN HOLDING ENGAGEMENT WITH ALL EXPOSED SURFACES OF SAID SECTION.